Nasdaq Calls Freeze 'Unacceptable,' Makes Changes to Avoid a Repeat

Nasdaq Will Use Manual Controls in Some Instances

By

Jacob Bunge

Updated Aug. 29, 2013 7:25 p.m. ET

Nasdaq OMX Group Inc. shouldered most of the blame for last week's unprecedented three-hour market outage, calling its performance "unacceptable" and saying the issues that caused the breakdown were within the exchange's control.

The admission—after a week of Nasdaq officials pointing fingers elsewhere—came in a summary of the...